Industrial power users are rapidly becoming aware of the importance of monitoring distributed power networks. Proper monitoring can provide tangible benefits with respect to equipment operation and maintenance; therefore, significant return on investment. More specifically, these benefits include savings in terms of equipment energy cost and maintenance costs, better equipment utilization, and increased system reliability.
Electric utility applications have ranged from supervisory control and data acquisition (SCADA) systems, primarily concerned with remote operations, to distribution automation, which focuses on operating efficiency. Certain utility applications have included devices mounted on power lines for sensing operating parameters of an associated power conductor. For example, in U.S. Pat. Nos. 4,158,810, 4,261,818, and 4,709,339, line mounted sensor modules have been described which measure the magnitudes of signal parameters associated with power lines. These parameters include current, voltage, conductor temperature and ambient temperature. Once captured by the sensor module, data corresponding to these parameters is remotely processed and evaluated.
Prior art systems of this type, although representing a significant improvement over traditional power line monitoring techniques, have a number of disadvantages. Among these disadvantages are the inabilities to efficiently and accurately measure the parameters associated with the power lines and to perform such measurements in a cost-effective manner. Moreover, the structures and techniques that have been used to implement these systems have been intolerably complex for many applications.
For many industrial applications, retro-fitting existing power systems with previously installed equipment is becoming a necessary step to provide a distributed power network monitoring system that is practicable. Unfortunately, the vast majority of such installed equipment was furnished with little or no remote communications capability. In those few systems having remote communications capability, the power sensing techniques provided thereby are incompatible with most of the recently developed systems and techniques.
Accordingly, there is a need for a monitoring system for a distributed power network that can be implemented without the aforementioned shortcomings.